Blindness

BLINDNESS OUTLINE INTRODUCTION EPIDEMIOLOGY CAUSES CATARACT GLAUCOMA CHILDHOOD BLINDNESS

INTRODUCTION 

WHO DEFINED BLINDNESS AS VISUAL ACUITY < 3/60 IN THE BETTER EYE.

EPIDEMIOLOGY  

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WOLRDWIDE IN DISTRIBUTION MAJORITY IN ASIA , AFRICA & LATIN AMERICA PREVALENCE;0.15-0.25% IN DEVELOPED COUNTRIES & UP TO 8.2% IN DEVELOPING COUNTRIES. 1% IN NIGERIA

CAUSES     

 

CATARACT GLAUCOMA TRACHOMA ONCHOCERCIASIS CORNEAL BLINNDNESS IN CHN; XEROPHTALMIA, MEASLES, OPHTALMIA NEONATORUM TRAUMA OPTIC ATROPHY; CONGENITAL, HEREDITERY, MENINGITIS, HYDROCEPHALOUS, BRAIN TUMOURS, ALCOHOL INTOXICATION, HEAD &

CAUSES CONTD        

ORBITAL INJURIES CONGENITAL CATARACT CONGENITAL GLAUCOMA SYSTEMIC DISEASE;DM, HT RETINAL DETACHMENT UVEITIS CORNEAL SCAR;INFECTIONS PTHYSIS BULBI UNCORRECTED REFRACTORY ERROR

CATARACT 

OUTLINE        

INTRODUCTION EPIDEMIOLOGY CLASSIFICATION FEATURES INVESTIGATION RX COMPLICATIONS DIFFERENTIALS

INTRODUCTION 

CATARACT MEANS OPACITY OF THE LENS. IT IS THE COMMONEST CAUSE OF TREATABLE BLINDNESS WORLDWIDE

EPIDEMIOLOGY 

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MAJORITY OF CATARACT OCCUR IN OLDER PEOPLE BECAUSE OF EXPOSURE TO ENVTAL AND OTHER IFLUENCES; INCRESED BLOOD GLUCOSE & UV RADIATION GREATER THAN 20 MILLION PPL WORLDWIDE ARE BLIND DUE TO BILATERAL CATARACT.

CLASSIFICATION 

AETIOLOGICAL             

SENILE TRAUMATIC PHYSICAL;PENETRATING/BLUNT RADIATION METABOLIC; DM, GALACTOSEMIA TOXIC;STERIODS,CPZ, BUSULPHAN MATERNAL INFXN;CMV,RUBELLA,TOXO MATERNAL DRUGS;THALIDOMIDE, STER PRESENILE ATOPIC DERMATITIS SYNDROMES;MARFAN, DOWN HEREDITARY SEC/COMPLICATING; ANT UVEITIS, HIGH MYOPIA

CLASSIFICATION CONTD 

MORPHOLOGICAL      

CAPSULAR SUBCAPSULAR CORTICAL NUCLEAR LAMELLA SUTURAL

CLASSIFICATION CONTD 

STAGE OF DEVELOPMENT     

IMMATURE MATURE HYPERMATURE INTUMESCENT MORGANIAN

CLASSIFICATION CONTD 

ACCORDING TO AGE     

CONGENITAL INFANTILE JUVENILE PRESENILE SENILE

CLINICAL FEATURES    

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WHITE REFLEX NYSTAGMUS, IF BILATERAL SQUINT, IF UNILATERAL OTHER OCCULAR ABNORMALITIES;MICROPHTALMOUS IMPARIED VISUAL ACUITY

INVESTIGATIONS      

MATERNAL ANTIBODIES IN RUBELLA ENZ STUDY IN GALACTOSEMIA BLOOD SUGAR URINE CHROMATOGRAPHY IN LOWE’S SERUM CALCIUM CHR ABNORMALITIES IN OTHER DZS

TREATMENT 

 

IN ADULT, IF INTERFERS WITH PATIENT’S QUALITY OF LIFE URGENTLY TREATED IN CHN MAINSTAY IS SURGERY

SURGERY 

INTRACAPCULAR CATARACT EXRACTION    

Displaced vitreous humour Zonular rupture Marfan’s synd Pt is too sick for ICCE

SURGERY CONTD 

METHODS CRYOEXTRACTION  VECTIS  WIRE EXRACTION  VACCUM  THUMBLING 

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EXTRACAPSULAR CATARACT EXTRACTION.

COMPLICATIONS 

PRE-OP   

TISSUE DAMAGE HAEMORRHAGE NERVE INJURY

COMPLICATIONS CONTD 

INTRA-OP HAEMORRHAGE  PERFORATION OF EYEBALL  TRAUMA TO OPTIC NERVE  CENTRAL RETINAL OCCLUSION  IRIS TEAR  HYPHEAMA  POST CAPSULE RENT  LENS LOST INTO VITREOUS  VITREOUS LOSS 

COMPLICATIONS CONTD 

EARLY POST-OP           

INFECTION SUB-CONJUNCTIVAL HAEMORRAGE CHEMOSIS WOUND BREAKDOWN IRIS PROLAPSE SHALLOW/FLAT ANT CHAMBER CHOROIDAL DETACHMENT HYPHEMA HYPOYON UVEITIS GLAUCOMA

COMPLICATIONNS CONTD 

LATE POST-OP          

EPITHELIAL INGROWTH CORNEAL OPACITY GLAUCOMA UVEITIS POST CAPSULAR OPACITY ENDOPHTALMITIS RETINAL DETACHMENT OPTIC ATROPHY MACULAR OEDEMA ASTIGMATISM

REHABILITATION   

INTRAOCCULAR LENS IMPLANT CONTACT LENS SPECTACLES

GLAUCOMA 

OUTLINE          

INTRODUCTION EPIDEMOLOGY AETIOPATHOGENESIS RISK FACTORS CLASSIFICATION CLINICAL TYPES INVESTIGATIONS TREATMENT COMPLICATIONS DIFFERENTIAL DIAGNOSIS

INTRODUCTION 

A MULTIFACTORIAL OPTIC NUEROPATHY CHARACTERISED BY VISUAL FIELD LOSS AND CUPPING OF OPTIC DISC USUALLY CAUSED BY RAISED INTRAOCCULAR PRESSURE.

EPIDEMIOLOGY 

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IT IS WORLDWIDE IN DISTRIBUTION AND AFFECTS PPL OF ALL AGE GROUPS. IT IS THE COMMONEST CAUSE OF IRREVERSIBLE BLINDNESS. IT AFFECTS AN ESTIMATED 1% OF THE POPULATION.

AETIOPATHOGENESIS 

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IMBALANCE BETWEEN THE PRODUCTION AND DRAINAGE OF AQUEOUS HUMOUR MECHANICAL COMPRESSION ISCHAEMIA OF THE OPTIC NERVE NORMAL INTRAOCCULAR PRESSURE  

10-21mmHg BY APPLANATION 12-25mmHg BY INDENTATION

RISK FACTORS         

PAISED INTRAOCCULAR PRESURE AGE >40 YEARS AFRICAN DECENT POSITIVE FAMILY HISTORY SYSTEMIC DISEASE; DM, HT, VASCULITIS, HYPOTENSION MYOPIA PROLONGED STERIOD USE TRAUMA MIGRAINE

CLASSIFICATION 

DEVELOPMENTAL  

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CONGENITAL INFANTILE

ACUIRED 

PRIMARY  

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OPEN ANGLE CLOSED ANGLE

SECONDARY     

TRAUMA OCCULAR SURGERY ASSCTED OCULAR; UVEITIS STEROID INDUCED RAISED EPISCLERAL VENOUS PRESURE

PRIMARY OPEN ANGLE GLAUCOMA  

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THE TRABECULAR MESHWORK IS CLEAR THERE IS INCREASED RESISTANCE TO THE OUTFLOW OF AQUEOUS WHICH LEADS TO INCREASED IOP CAUSES; 

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THICKENING OF THE TRABECULAR MESHWORK WHICH REDUCES PORE SIZE REDUCTION IN THE NUMBER OF LINING TRABECULAR CELLS INCREASED EXTRACELLULAR MATERIAL IN THE TRABECULAR MESHWORK

CLINICAL PRESENTATION     

USUALLY ASYMPTOMATIC UNTIL LATE OCCULAR PAIN HALOES DEFECTIVE VISION TIRED EYES

EXAMINATION       

REFRACTION FUNDOSCOPY GONIOSCOPY SLIT LAMP EXAMINATION TONOGRAPHY TONOMETRY PERIMETRY

ASSOCIATED FACTORS      

FAMILY HX OF GLAUCOMA MYOPIA RETINITIS PIGMENTOSA RETINAL VEIN OCCLUSION DM DIFFERENTIAL DIAGNOSIS   

ISCHAEMIC OPTIC NEUROPATHY LOW TENSION GLAUCOMA OCCULAR HYPERTENSION

CLOSED ANGLE GLAUCOMA 

THERE IS MECHANICAL CLOSURE OF THE AQUEOUS DRAINAGE DUE TO CONTACT BTW THE IRIS & TRABECULAR MESHWORK OR PERIPHERAL IRIS & CORNEA

CLINICAL PRESENTATION            

HX OF PAST SIMILAR EPISODES SUDDEN DEFECTIVE VISION HEADACHE UNIOCCULAR PAIN NAUSEA VOMITTING HALO CONJUNCTIVAL CONGESTION CORNEAL CLOUDINESS & OEDEMA SHALLOW ANT CHAMBER FLARE SEMIDILATED & NON-REACTIVE

NORMAL TENSION GLAUCOMA 

THERE ARE VISUAL FIELD LOSS & CUPPING OF THE OPTIC DISC

 CONGENITAL  

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GLAUCOMA

MAY BE PRESENT AT BIRTH OR WITHIN THE FIRST YEAR SYMPTOMS VIZ; EXCESSIVE TEARING, INCREASED CORNEAL DIAMETER, PHOTOPHOBIA,DIFFUSE CORNEAL OEDEMA ASSCTED SYND; STURGE-WEBER,LOWE,S

SECONDARY GLAUCOMA 

TRAUMA,UVEITIS ETC

TREATMENT 

MEDICAL     

B-BLOCKERS PARASYMPATHOMIMETICS SYMPATHOMIMETICS PROSTAGLANDIN ANALOGUES CARBONIC ANHYDRASE INHIBITORS

TREATMENT CONTINUED 

LASER  

 

LASER TRABECULOPLASTY LASER IRIDOTOMY

CYTOPHOTOCOAGULATION SURGERY 

TRABECULECTOMY